This invention relates to an emulsion of water, at least one surfactant, and a polymethylalkylsiloxane. A method of using the emulsion for the treatment of organic surfaces such as rubber and vinyl is also disclosed.
One of the most important commerical applications of rubber is the pneumatic tire. Because of the increased demand for speed and endurance in modern vehicles, it has become necessary to design rubber compounds and build tires with such factors in mind. Tires must be designed to withstand heavy loads and high speeds for prolonged periods of time, and the body of the tire must be capable of withstanding severe shock, and must not exhibit excessive heat build-up. In addition to performance, a tire should also have a clean, shiny, appearance. Heavily soiled tires can detract from the appearance of an otherwise expensive vehicle. Most often, soiled surfaces of tires are caused by rain, dirt, road salt, water, and snow.
Aqueous emuslion of polydimethysiloxane fluids have been applied to many surfaces as a protective coating including rubber, vinyl, plastic, leather, and sealed wood. Some of these surfaces have also been found to have been rendered anti-static for the purpose of repelling dust and dirt. However, when such emuslions are employed as protective coating in outdoor applications, such as the sidewall of an automboile tire, the polydimethlsiloxane coatings are rapidly removed and rendered ineffective by water which is encountered while driving in rain or snow. In order to restore the appearance of the soiled tire, another and more often, repeated applications of the polydimethlsiloxane emulsion is required. This, of course, is a disadvantage and a time consuming task. Exemplary of such polydimethylsiloxane emulsion coatings are U.S. Pat. No. 3,956,174, issued May 11, 1976, and U.S. Pat. No. 4,133,921, issued Jan. 9, 1979.
In accordance with the presenct invention, new and improved protective coatings for surfaces such as rubber are provided, and in which frequent reapplication of the coating is not required. The coatings of the present invention are directed to emulsions containing polymethylalkylsiloxanes, rather than polydimethylsiloxanes as in the prior art. Such coatings have been found to possess superior gloss, luster, shine, and repellent characteristics, and soiled surfaces may be merely rinsed clean without requiring frequent reapplication of the coating to a tire sidewall, for example. While polymethylalkylsiloxanes are not new as evidenced by U.S. Pat. No. 4,640,792, issued Feb. 3, 1987, emulsion of such compounds and their application to surfaces such as rubber and vinyl as protective coatings is new and novel.